Here is the back side of one of the shirts:
niiiiiiiiiiiiiiiice!
Like I said before, I only used 4 spot colors. I can separate the colors as bitmaps, but not vectors (at least without doing a bunch of work. Here is the pantone blue color:
niiiiiiiiiiiiiiiice! If you can do it, your printer
should be able to do it.
When it comes to vector, I have no issue separating colors if they were all flat. It's not too different from doing layered vinyl work. So I get that, But when you throw gradients (or transparencies) into the mix, that is when I struggle.
It's the same thought process, but think in objects rather than color. A gradient should be the same color from end to end in one object. 100% pantone blue to 0% pantone blue, for example, is the
same spot color as the flat color that you understand. That's where most people get hung up --- understanding the gradient as one "color."
Defining transparency, is fairly simple, too. It's understanding how the computer works with the effect and the appropriate terminology.
Think in 3 dimensions. The goal is to lay one color on top of another color to create a third color. On your GTO, a shadow from the fender makes a portion of the red on the tire darker.
Again, I forgot how Corel works, but in Illustrator a
transparency will mix two colors on one level. The shadow tint of black over the red will physically change the overlapping color to dark red. ...like mixing paint. only it's CYMK. However, for printing, someone will want to deconstruct that by figuring out how to get all the black molecules out of the red molecules ...and that's when the whining starts.
However,
Overprint will suspend the shadow tint of black over the red to give the
appearance of a dark red... like laying transparent vinyl over another color to create the third color. ...ahhhhhhhh, that's much easier to
rip black molecules off of red molecules. (The RIP pun was intended - LOL)
That's how the illustration software understands it when one goes to print the color separations.
Hopefully, that's understandable and clicks with you.
Has anyone used "simple seps"? Would it be worth it for me to get something like that, or do the screen printers have this type of software?
The software like you posted has some sort of algorithm/action/process to do the same thing you're doing without you understanding what it's doing.
...for better or worse.
It shouldn't be something, you need to buy. Production shops will typically have something of that nature... Fast Films, Spot Process, some version of index color seps. But with this particular design, you may be past using something like that for anything other than experimentation and education. Then too, a competent shop will want to massage the design a bit, so that it will be easy for them to set up for production based on limitations of their equipment. Either they will take ownership of it, and do it. Or, be able to communicate to you what would work best.
There is a 10 play Demo on the site you could try if you wanted, though.
With what I've seen of your work for t-shirts, the designs aren't really all that complex.
Your gift for effective simplicity is awesome! Heck, if I had a screen print shop in Pontiac, I probably wouldn't need to spend more than an hour showing you a couple tricks on how to set-up art for production. Then, deeeeeeeeeeep discounts/commissions/kick-backs, whatever you wanted, on anything you supplied and next day delivery... LOL.
Do you need to print a white underbase for colored shirts?... 
